good luck, im on linux completely for couple of years, its not been easy but i have adapted my needs to the universal operating system
i myself ordered an orange pi for the portability
if you want to learn linux, i think it would be more convenient to just use a bootable usb flash drive and x86 pc's (laptop/desktop with intel/amd)
the main reason being that x86 architecture is better supported, and with the right distro, you can just boot up the usb on any pc, and have drivers for any device
on x86 there are livecd-isos (wich you can boot without installing, even from usb), dont know if theyre available for arm architecture
but progress is made on arm too, and hopefully soon, it gets the same support as x86
but the most important advice is to keep searching, keep asking, and never give up
its not hard to learn, you just need to know where to ask